Check the PATH of your Mac with echo $PATH
Anytime that you run a command through the Terminal directly by a command name like ls or dscacheutil, your Mac is looking through a series of directories for that command to exist. This list of directories is called the PATH, and it’s a carry over from the unix underpinnings of Mac OS X. As you may have guessed, checking your PATH in Mac OS X is the same as it is in most other unix variants:
Executing that command, you’ll see something like:
$ echo $PATH
The directories listed are those that are searched for commands. So the next time someone asks you if a directory is in your path, now you know where to look.